Can you crack it?

[1vRz3TCk]

GCHQ spy recruitment code, Can you crack it?

http://www.canyoucrackit.co.uk/

P.S. do you know any more sites like this?

[andywestken]

If you're a student, there's
http://www.crypto64.com/2011/08/14/crypto-challenge-2011/

This site requires you to create an account to get at the challenge. And there's just under a month's time left! (Started 1 Oct, ends 31 Dec)

[1vRz3TCk]

I haven't been a student for a long time. :0(

But I am starting to get increasingly interested in Cryptography.

[Moschops]

The GCHQ one requires more than a passing acquaintanceship with shellcode, for starters. This is not going to be a ten minute letter substitution hack. Sadly :(

[Fa Li]

> do you know any more sites like this?

If you like more different crypto challenges open for everyone:
see www.mysterytwisterc3.com.

There are about 80 challenges. Some are really fancy. Most of em offer some educational help.

[hamsterman]

Are we supposed to read one word out of all that? Is it even possible? I have a feeling there's an infinite number (well, 2^1280 in this case) of ways to represent a string.. And I'm sure they wouldn't use a common primitive chipper..

[1vRz3TCk]

hamsterman wrote:

Are we supposed to read one word out of all that?

I’m not sure. My initial thought is that it is a piece of text encoded with a key and you have to deduce to key to continue. But then I thought that it could be just the plaintext they are after…as the hex is an image file, have they used steganography…are you meant to just hack the site…or is it all and the real test is to see how you tackle it?

hamsterman wrote:

Is it even possible?

I'm sure that it's possible...just very hard (at least for me with the limited knowledge I currently have). It would be a fairly pointless 'test' if it was not possible.

[hamsterman]

I'm sure that it's possible...

My point is that I could apply one algorithm and get "banana" or another and get "pineapple". There would be no way to know which is right, except for trying to submit them all. If it was a text, I think you could rely to some extent on natural repetitions of letters, but "keyword" implies a single word.

[firedraco]

That's the principle behind a one-time pad cipher actually. However in this case, I would assume that the correct cipher would have a meaningful key (like "ilikecats"), whereas the useless messages would have a meaningless key (like "ai8iginuuaswe").

[ascii]

Cool site. I'm operating on a lot of assumptions on the moment however. Assuming each set of two characters represents a single character, I guess I'll start by finding which one of those appears the most and making that the most common letter in english (I think it's 'e', but I'll have to look it up).